1. Field of the Invention
This invention relates to coal gasification. More especially, this invention relates to a process and apparatus for producing synthesis gas by partial oxidation of carbonaceous solids suspended in water.
2. Discussion of Prior Art
German Offenlegungsschrift 23 09 821 describes a burner and a process for producing synthesis gas by partial oxidation of hydrocarbons and slurries of solid, carbon-containing fuels in liquid hydrocarbons. The burner consists of a central, axial tubular gas line joined to two further tubular inlets concentrically arranged relative to this line. In order to carry out the process, oxygen may be added to the reaction via the central axial line, and a hydrocarbon or a slurry of solid hydrocarbon-containing fuels in hydrocarbons via the middle line concentrically surrounding the said dentral feed line.
A temperature-regulating gas is introduced via the outer concentric line. A gas or gas mixture which reacts enothermically in the formation of synthesis gas is used as temperature-regulating gas. Water in the form of droplets or stream, and inert gases such as nitrogen and carbon dioxide are recommended. Steam and carbon dioxide are preferred as the temperature-regulating gas since inert gases have the disadvantage that they merely dilute the reaction product. The purpose of this temperature regulating gas is to effect the reaction temperatures and suppress the back-mixing of already formed synthesis gas in the zone of partial oxidation.
The disadvantage of such process is that the coal-water suspensions are not converted to the desired extent into synthesis gas. It is true that a temperature control is achieved when using an outer inert gas stream, though at the expense of the conversion, with the result that unreacted carbon fractions remain in the gas stream.